you called number of pages he read on second day = PThat's OK. ButAccording to your formulaP + .20P = 60If I define it so than(no. of pages on second day) + (20% of no. of pages on second day) = 60Which is wrong!!!!!because as in question no. of pages on second day are 20% less than 1st day. The formula should beP + .20*60 = 60P + 12 = 60P = 48